This is an old thread... and my old story about knee problems.
In 1995, I was diagnosed with right knee problems. I used a taping technique to pull the kneecap over while I ran so it would track properly. A year or so later, I switched to ChoPat knee straps that forced the kneecap to run in its proper grove. About 5 years later, it dawned on me that my kneecap not tracking properly was a form problem. I switched from severe heel striker to forefoot running and my knee problems went away. I continued to wear ChoPats for a couple more years and finally tried running without them. I was cured.
In my opinion, most non-tramatic... i.e., not torn ACL, meniscus, MCL, etc... are caused by poor shoes and/or poor running form combined with runners being too undisciplined to stop and assess potential injuries before they get worse.
Runners are hardwired to "run through the pain." It's a badge of honor to brag about finishing a run or a race after an injury. This is stupid and shows a lack of self-discipline and loss of perspective of the bigger goals.
Countless times, I've heard this story. "I was two miles into my run when I felt this twinge in my knee. It hurt, but I hobbled along to finish my 10-mile run. The next day, my knee was so swollen! It's been two weeks and I still can't run!"
You really, really have to listen to your body and take potential injuries seriously.
Finishing a workout today is never more important than avoiding exacerbation of an injury that could keep you from running for the next six weeks!